Responsibilities of Shipboard Scientists

(Revised 6 August 1998)

Overview

Scientific participants are invited to perform particular jobs that need to be completed to ensure the
success of the cruise. An individual's scientific expertise is taken into account as much as possible
during job assignments. There may not always be a one-to-one relationship between an
individual's expertise and objectives and the required job. In such a case, shipboard scientists
should be aware that they are responsible for contributing to the overall leg objectives as outlined in
the Prospectus in the most effective way possible prior to completion of auxiliary science
Information on shipboard laboratories.

Core Description

Core describers may have expertise in a wide variety of fields including sedimentology,
petrography, petrology, or structural geology. The optimal mix of expertise is determined by the
leg objectives and the individuals selected by the Co-chiefs, the Manager of Science Services, and
the Staff Scientist. Core description may involve the following tasks:
 macroscopic visual description of split cores, entered in the core description database
which generates the "barrel sheets" (sediments) or in more detailed core section graphic templates
(igneous rocks);
 microscopic observations from smear slides and/or thin sections are written to word
processing files and, in some cases, added to the macroscopic description forms;
 acquisition of physical property data with the split-core track, including diffuse color
reflectance, magnetic susceptibility, and digital images; may also be done by the individual in the
physical properties position;
 preliminary interpretation of depositional, diagenetic, magnetic, or deformational
processes;
 selection of samples, in consultation with other scientists, for carbonate, XRD, or XRF
analysis;
 analysis of XRD and/or XRF data, if the appropriate expertise exists (otherwise don't
bother collecting these data on the ship); may also be done by the individual in the geochemistry
position.

StratigraphicCorrelation

Stratigraphy correlators are key positions on legs where complete stratigraphic sections (achieved
by coring multiple holes at a site) are an essential component of the leg objectives. Completion of a
meters composite depth (mcd) depth scale in near-real time guides coring operations and ensures
complete stratigraphic coverage. For maximum efficiency, two correlators are needed to cover a 24
hour period and to guarantee feedback within hours. Correlation is achieved using a Sun
workstation and the customized program "Splicer." Precruise training is required for inexperienced
correlators. The position typically also includes operation of the multisensor track since the main
data sets used are magnetic susceptibility, natural gamma radiation, and gamma-ray attenuation
density from whole-core logging. Other data may be needed to improve correlation such as color
reflectance logs, macroscopic descriptions from split cores, or biostratigraphic information.

Biostratigraphy

Shipboard micropaleontologists provide age data and an age/depth model for each site. This is
done using (a) core-catcher samples as soon as possible after a core is recovered, and (b) additional
samples, up to one per section, in at least one hole per site. For nannofossils, and sometimes
diatoms, toothpick samples may be taken from the open ends of core sections on the catwalk. For
other microfossil groups, samples taken in addition to the core catcher samples have to be taken
from the split core working halves. Some stratigraphic boundaries may be analyzed in higher detail
on ship, using samples taken from the split working half cores. Full assemblage analysis is not
necessary on ship; rather, identification of useful microfossil datums for constructing age/depth
plots and sedimentation/ accumulation rate curves is the primary emphasis. Microfossil datums are
also used for integration with multisensor track data for core/core correlation and construction of
spliced composite sections. Paleoenvironmental or bathymetric data, principally from benthic
foraminifers, may also be of primary importance on certain legs. Shipboard micropaleontologists
process their own samples, and have a fully equipped processing lab with two acid hoods for this
purpose. A variety of slides, mounting media, and
maceration chemicals are available for all major microfossil groups. A reference library with texts,
journals, and reprints is available to help shipboard paleontologists identify microfossils. Because
of limited shipboard space, this library is not comprehensive, and micropaleontologists should
check with ODP before their leg to see what references are available. Micropaleontologists are
advised to bring their own set of references to supplement the shipboard library. A computer
image database of nannofossils is also available on a PC in the paleontology lab.
Micropaleontology Reference Collections (MRC) are available at a number of institutions
worldwide, that contain reference slides of planktonic foraminifers, diatoms, calcareous
nannofossils, and radiolarians from DSDP and ODP cores. Scientists may visit these collections
to view material before sailing. Check the MRC webpage for information about using these collections.

Magnetostratigraphy

Paleomagnetists conduct or supervise paleomagnetic measurements and reduction of
paleomagnetic data to intensities and direction of magnetization. Paleomagnetists also provide
absolute orientation data for deformational structures measured in the core, if appropriate. Some
additional rock magnetic properties can be acquired on the ship, which can be particularly useful if the
magnetic properties are (partly) ephemeral (post-recovery dissolution, reduction, or oxidation of
magnetic minerals). For detailed information, see ODP Technical Note 18
or the paleomagnetism lab.

PhysicalProperties

Scientists assigned to this job usually determine the following properties:
 moisture content and grain density on core samples
 P-wave velocity on split cores and/or core samples
 thermal conductivity on full cores or split cores, if appropriate
 vane shear strength on split cores, if appropriate
In addition, they oversee and document the overall physical properties measurement program in
consultation with other scientists, including the full core and split-core logging systems. They also
ensure that calibrations and control measurements are carried out according to protocol to ensure
data quality control. For detailed information, see the physical properties handbook (ODP Technical Note 26).

Downhole Logging, Geophysics

This job includes the following:
 advise the co-chief scientists on the logging program for the cruise;
 work closely with the Lamont-Doherty Earth Observatory logging scientist in designing,
implementing, and interpreting the logging program; and
 assist the Schlumberger field engineer with data acquisition if required.
This position often includes responsibility for other geophysical tasks, such as:
 acquisition, analysis, and presentation of downhole temperature measurements;
 seismic data acquisition and presentation (site surveys);
 construction of synthetic seismic profiles.
On rare occasions, specialists may sail to perform more specialized measurements, which may
include:
 microbiological sampling and analysis;
 packer experiments;
 installation of CORKs;
 vertical seismic profiling.